Теряю рассудок Причина Получение основных данных всегда возвращает ошибку

Ладно, сразу к делу ...

это первый раз, когда я использую Magical record From Magical Panda. Я следил за уроком от http://yannickloriot.com/2012/03/magicalrecord-how-to-make-programming-with-core-data-приятный/

а вот мой код

Person.h

@property (nonatomic, retain) NSString * firstname;
@property (nonatomic, retain) NSString * lastname;
@property (nonatomic, retain) NSNumber * age;

AppDelegate.M

@implementation AppDelegate

- (void)dealloc
{
    [_window release];
    [_viewController release];
    [super dealloc];
}

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
     [MagicalRecord setupCoreDataStackWithStoreNamed:@"MyDatabase.sqlite"];
    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
    // Override point for customization after application launch.
    self.viewController = [[JASidePanelController alloc] init];
    self.viewController.shouldDelegateAutorotateToVisiblePanel = NO;
  //  self.viewController = [[[ViewControllerCenter alloc] initWithNibName:@"ViewController" bundle:nil] autorelease];
    self.viewController.centerPanel = [[UINavigationController alloc] initWithRootViewController:[[ViewControllerCenter alloc] init]];

    //UINavigationController *navContorller=[[UINavigationController alloc] initWithRootViewController:self.viewController];
    self.viewController.rightPanel = [[NetraRightWindow alloc] init];
    self.window.rootViewController = self.viewController;
    [self.window makeKeyAndVisible];

    return YES;
}

- (void)applicationWillResignActive:(UIApplication *)application
{
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
    // Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
}

- (void)applicationDidEnterBackground:(UIApplication *)application
{


    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later. 
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}

- (void)applicationWillEnterForeground:(UIApplication *)application
{
    // Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
}

- (void)applicationDidBecomeActive:(UIApplication *)application
{

}

- (void)applicationWillTerminate:(UIApplication *)application
{
     [MagicalRecord cleanUp];
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}

@end

это мой метод сохранения:

-(void)fetchRecords{

   NSManagedObjectContext *localContext= [NSManagedObjectContext MR_defaultContext];

    // Create a new Person in the current thread context
    Person *person                          = [Person MR_createInContext:    [NSManagedObjectContext MR_defaultContext]];
    person.firstname                        = @"Test";
    person.lastname                         = @"merdeka123";
    person.age=[NSNumber numberWithInt:123];

    [[NSManagedObjectContext MR_defaultContext] MR_save];
    NSArray *Result=[Person MR_findAll];

    NSLog(@"Result==%@",Result);

и результат:

2012-11-25 15:43:38.033 Trip[10491:15e03] Cok==(
    "<Person: 0x866fe40> (entity: Person; id: 0x866e170 <x-coredata://15583C03-3EB4-479B-9EF2-B0BC750FC987/Person/p1> ; data: <fault>)",
    "<Person: 0x866fe80> (entity: Person; id: 0x8670210 <x-coredata://15583C03-3EB4-479B-9EF2-B0BC750FC987/Person/p2> ; data: <fault>)",
    "<Person: 0x81471a0> (entity: Person; id: 0x815c2a0 <x-coredata://15583C03-3EB4-479B-9EF2-B0BC750FC987/Person/p3> ; data: {\n    age = 123;\n    firstname = Test;\n    lastname = merdeka123;\n    time = nil;\n})"
)

почему это всегда ошибка данных? это проблема в магической записи? или что-то не так в моем коде?